Identification Of Cytoplasmic Male Sterile Lines Of Maize And The Differences Comparison With The Maintainer

The use of cytoplasmic male sterility(CMS) in hybrid seed production is the effective way of utilization of heterosis in maize, however, cytoplasmic male sterile lines still exist some difficult problems to overcome in the application of hybrid maize production, resulting in few application in hybrid seed production in maize. Therefore, depth study of maize cytoplasmic male steriler of sterile mechanism, and the relevant performance characteristics, have very important significance for breeding excellent maize cytoplasmic male steriler that can be used for hybrid seed production. The study made a detailed analysis of fertility, resistance, cytological, physiological and biochemical characteristics, cytoplasmic type, and potential utilization of four cytoplasmic male sterility of materials, in order to provide a reliable basis for the use, and provide more powerful evidence for revealling maize male sterility mechanism finally. The results are as follows:1. Fertility and cytoplasmic type identification of sterilers showed that DT-he344, ZT-he344 and 85218 A anthers were thin, atrophy, no exserted, no cracking, and DT-he344 and ZT-he344 were abortion type of no pollen grains; 85218 A had pollen grains, but was wizened and no activity. T103, DT-he344 and ZT-he344 were T-type cytoplasmic male sterile lines, and 85218 A were C-type cytoplasmic male sterile line.2. The steriler and maintainer were inoculated by bipolaris maydis and the results showed, the steriler 85218 A resisted to bipolaris maydis T race highly, moderatly resisted to bipolaris maydis C race; the steriler DT-he344 and ZT-he344 were sensitive of bipolaris maydis T race, moderatly resisted to bipolaris maydis C race; maintainer he344 and 85218 B showed resistance to bipolaris maydis T and C race highly.3. Cytological analysis showed that the steriler 85218 A microspore began aborting from dyad stage, aborting characteristics were significant in monocyte late period. The abortion period of the steriler DT-he344 and ZT-he344 were from monocyte early period to monocyte mid period, the pollen abortion had a direct relationship with the occurrence of the abnormal anther wall tissute.4. The results about comparison of physiological indexes showed that the ROS content in tasseling and anthesis stage of 85218 A leaves was lower than 85218B; ·OH scavenging rate, MDA content were higher than the 85218 B. The POD、CAT and APX activity in tasseling stage of 85218 A leaves were significantly lower than 85218 B, Pro and soluble sugar content were no significantly different between 85218 A and 85218 B leaves, but the soluble protein content was significantly higher than that of 85218 B in anthesis stage. The physiological indexes were not difference in the he344, DT-he344 and ZT-he344 leaves.The content of ROS, metabolites and POD, CAT and APX activity in 85218 A anther were significantly lower than 85218 B during most of the tassel growth. The, MDA content and POD activity of the steriler DT-he344 and ZT-he344 were higher than that of the maintainer. With the development of tassel, the activity of SOD, CAT, APX and soluble protein content in the he344 were higher than that of the steriler gradually. After microspore gestation, the contents of H2O2, Pro and soluble sugar in steriler were significantly lower than those in the maintainer.5. The test breed yield results showed that there was no significant difference between the steriler T103 and the maintainer HD103. Because the tested lines and the test lines had interaction effect, he344, DT-he344 and ZT-he344 came into difference for test breeds yield, the tested line itself did not produce significant difference for test breeds yield. Compared with 85218 B, 85218 A had the effect of increasing yield and it can increase ear length and 100-kernel weight of the test breeds, interaction effect on 85218 A and the test lines increased the test breeds ear diameter and reduced bald tip henlth.